Design and implementation of a novel adaptive backstepping control scheme for a PMSM with unknown load torque

Abstract

In this study, a novel adaptive backstepping control method is proposed to handle the position tracking problem of the permanent magnet synchronous motor (PMSM) system with unknown load torque. Firstly, a novel load torque update law which is different from the traditional load torque update law is obtained based on the position error and estimated torque error. Then, a novel adaptive backstepping controller is presented under the circumstance of estimated load torque. The asymptotic stability of the overall system is verified by using Lyapunov stability theory. The novel load torque update law guarantees the accurate estimation and improves the convergence speed of the estimated load torque. The designed controller improves the position tracking performance and ensures stability of the closed-loop system. Finally, real-time experiment results with LINKS-RT platform intuitively exhibit that the proposed control method ensures position tracking performance and retains good load torque disturbance attenuation.